Moe Freedman links to Jeffrey Goldberg on the risk posed by Iraq, and ends by quoting Robert Gates: "A fifty-per-cent chance of such an attack happening is so terrible that it changes the calculation of risk."

Update
Isn't the best way to think of a war in Iraq in terms of the risks we'll undergo if we don't attack? Speaking for myself, an Iraqi attack (or an Iraqi-assisted attack) on a big US city might not be such a big deal. But symbolically, for most Americans, the shock would be terrible. So most Americans should support a war in Iraq.